The force is trying to reduce its budget by $400 million a year and on Tuesday announced it will scrap seven of its 10 military bands.

McKenzie, a mother-of-two from Epsom, took to Twitter in November last year to voice her concerns over the eligibility changes, something she was later ''told off'' for by her bosses.

She targeted some of her concerns at the Twitter accounts of politicians including National's Tau Henare, whose son was a cadet, and Labour MP Trevor Mallard.

On several occasions in late November she linked to a petition, organised by a cadet, to keep the age rule as it was.

Then on December 5 she tweeted her unit had farewelled 10 cadets the previous evening because of the change.

''There were tears shed,'' she said.

The same day she tweeted Mallard estimating 330 cadets nationwide would be affected.

Despite having already been warned, McKenzie took to the internet again earlier this year, this time on Facebook, voicing her concerns about other proposed changes.

Age limits were being placed on promotion courses that allowed cadets to move up the ranks.

McKenzie said her Facebook profile was private but friends from the Cadet Force could see it. However, by tagging MPs Jonathon Coleman, Nikki Kaye and Henare, her updates also became visible to them.

She has organised a meeting with Henare after Easter.

McKenzie had volunteered with her Auckland unit since 2004, and had been a cadet herself between 1989 and 1996.

She said she was disappointed with the way the change was implemented with no consultation or a phasing-in period so current cadets over the age of 18 weren't affected.

''My main concern for units is that you'd lose all your senior cadets and therefore all your institutional knowledge. It makes it hard to run leadership activities without the senior cadets there to lead them.''